Production of gas suitable for the synthesis of hydrocarbons from carbon monoxide and hydrogen



H. KOPPERS Oct. 1l, 1938.

2,132,533 E SYNTHESIS 0F HYDRocARBoNs PRODUCTION OF GAS SUITABLE FOR TH FROM CARBON MONOXIDE AND HYDROGEN F'lled Sept. 5, 1930 2 Sheets sheet 'l Om, mM

m, .LIQ html S Oct. 1l, 1938.

PRODUCTION OF H. KOP

PERS

GAS SUITABLE FOR THE SYNTHESIS OF HYDROCARBONS FROM CARBON MONOXIDE AND HYDROGEN Filed sept. s, 1956 2 Sheets-Sheet 2 @Lulu Mw@- Patented Oct. 11, 1938 UNITED STATI-:s

PRODUCTION F GAS SUITABLE FOR THE SYNTHESIS OF HYDROCARBONS FROM CARBON MONOXIDE HYDROGEN Heinrich Koppers, Essen, Germany, assigner, by mesne assignments, to Koppers Company, Pittsburgh, Pa.,'a corporation of Delaware Y Application September 3, 1936, vSerial No. 99,327

In Germany September 6, 1935 Y v2 Claims.

The invention yrelates to the production of gases, suitable for the catalytical synthesis of hydrocarbons, for instance motor fuel, from carbon monoxide and hydrogen and especially to such a processfor producing said gases,which work continuously, so that a continuous stream of useful gasesmay be obtained.

In the catalytical synthesis `of hydrocarbons, for instance by the process of Professor .Dr. Fischer and collaborators, a gas mixture is treated which consists essentially of carbon monoxide and hydrogen, preferably in a ratio of 1:2, besides some unavoidable inerts. Such a gas mixture is brought into contact with catalysts, such as finely divided cobalt or nickel compounds, at normal or slightly increased pressure, whereby hydrocarbons are formed and water is split-olf.

Inmy co-pending application, Arelating to the Continuous production of water gas, executed May 29th, 1936, Serial Number 84,398, filed June 10, 1936. I disclosed anew and useful process for the production of water-gas from reactive fuels, for instance brown coal, lignite or other bituminous, non-caking coals or fuel.

My former process provides for a continuous stream of water-gas and steam, which in one stage of the process is heated-up to a high temperature and in a second stage is brought into contact with the carbonaceous material to be treated, whereby the steam reacts with the carbon, forming water-gas, i. e., amixture of carbon monoxide and hydrogen with some inerts.

The principal object of my present invention is to provide such improvements in my former developed process, corresponding to my said copending application,I which permits a higher yield of useful gases, suitable for the synthesis of hydrocarbons, and containing a high percentage of hydrogen, so that the ratioy of carbon monoxide to hydrogen in the gas mixture is 1:2 or nearly 1:2.

My present invention follows the principle of converting as much hydrogen as possible contained in the fuel to be treated, for instance bituminous substances, into elementary hydrogen, so that as much carbon of the fuel as possible may be consumed for the production of carbon monoxides, and therefore a high efficiency of the process, regarding the fuel consumption, may be obtained. In other words, according to my invention I transform the fuel including its bituminous matters, as far as possible into carbon monoxide and elementary hydrogen, these two substances being the basis for the production of Well dened hydrocarbons, whilst the recoveryv of y bituminous matters of the fuel inthe usual form of tar and distillation oils is reduced or wholly omitted. v Y

The process according to my` present' invention consists essentially in that preferably reac-` tive fuels, such as brown coal or lignite'coalL or any other suitable bituminous fuel aretreated in a cycle with a mixture of steam andwatergas, said mixture being heated at one stage of the cycle to such a temperature, at which hydrocarbons will decompose and interact with steam, and in a second stage the hot. gasmixture is brought into contact with the fuelto be treated, the gases thus produced being returned wholly or partly to the heating stage of the process at a temperature'above the dew point, with regard to water and tarry matters, steam being added to said gas, if necessary, before it enters the heating stage. f

Furthermore, my invention provides for sub-f stances removed from the circulating gases, such as tarry matters, being in the form of mist and dust, to be treated in such a manner, that hydrocarbons *contained in such residuals may' be wholly or partly added to the circulating gases before they enter the heating stage of the process. This feature of my present invention is insofar advantageous, as it permits to use also the hydrocarbon contents of the tarry matters, removed from the gases for the production of elementary hydrogen, useful for producing water-gas with a defined ratio of carbon monoxide and hydrogen.

Still further objects of my present invention may be taken from the following description of a preferred embodiment of my invention, which Ifwill explain in particular on the lines of the accompanying drawings.

On the drawings, Fig. 1 shows a side view and partly a vertical section through a plantv for the continuous production of water-gas, and Fig. 2 shows the internal construction of the gas producer in more'detail.

In the plant as shown in the drawings, a gas vproducer l serves for receivingthe' fuel to be gasied. Preferably a so-called easily reactive fuel shall be used, for instance brown coal, lignite, bituminousnon-caking coal, wood, shells of coconuts or any other suitable fuel containing carbon. In gas producer l, the fuel is `brought into contact with a highly heated mixture consisting of water-gas and steam. The hot gassteam-mixture thus transfers heat'to the fuel and warms it up to such a high temperature, that by thereaction of the steam with carbon, hydrogen and carbon monoxide, i. e., water-gas, are formed.

The design of the plant may be the same as described in my aforesaid co-pendng application, executed May 29th, 1936, Serial Number The gas producer I consists of two rectangular refractory brickwork. Inthe ceiling` ofthe Vgas producer are arranged suitable fuel feeders 3.,y The contrivance 3 may be essentially c'jfsimilar' design as the well-knownV charging Vcontrivances for gas producers. 3 e

Inside the gas producer I therelare provided a row of bridges 4, made of4 refractry mai terial. In Fig. l of the drawingsfthese bridges `4 '-I'he bridgesY 4 have the shape of cutters at the topf a Inside the bridges 4 there aren provided longi-V have been shown in dashed lines.

bustion 'shaftf'lL made of refractory material.

The connection Vof the Vpipeline '6 with the shaft 'I canbe interrupted by a valve 8 or another suitable closing agent, which is able to withstand high temperaturesf YAtthe upper end at point 9 the shaft l'I Vis Yin vconnection with the upper end ef a tower-like gas vheater I0', designed vessentially like the well-known ACowpers used for heating air in the, blast-furnace process. vAn annular wall projection I2@ is provided abovethe bridges 4 in the Ygas producer, the cavity I2b of the vprojection being connected with a wall-channel I2C, which is connected by channels I2 with dust separators I3. The gases contain often large quantities of dust, which have to be removed before the gas can be further treated. The dust precipitating n the dust separators I3 is discharged at the bottom of the separating chambers. A pipeline I4 leads from the dust separators to the steam boiler I5, or to anotherY suitable heat exchanger, in *which the hot gases Vgive off their heat. From the contrivance I5Y the'c'ooled gases pass through the pipeline IB to a scrubber I T, in which the gases are treated with hot and/or cold Water and are .thus freed from the last traces of dust and other impurities. The contrivance I'I is in connection with agas exhauster orfan I8, by means of the pipeline I9. From the exhauster I8 the puried and cooled gas can be drawn olf through the pipeline 20 forV further use.V

In the ceiling of the gas producer, Van opening 5I is arranged fr, through which the gases formedn in the upper part of the gas producer can escape. A pipeline 2I is connected to saidV gas outlets, whichpipeline leads to a Vdust-separator '2.2. `From the dust separator 22 a pipeline 23 leads to a tar .removal arrangementY 24, for instanceV to an electrostatic tar precipitator. The pipeline 231and the dust separator 22 are preferably lined' with Van heat insulating material, so that the gases .cannot Ybe cooled down there. From the tar precipitator 24 a pipeline 25 leads to the gas exhauster or fan 26. This gas exhauster 26 is suitably directly coupled with the gas exhauster, so that both gas exhausters can be driven by one motor 21.

The temperatures of the gases passing the outlets, arranged in the upper part of the gas producer, may be above preferably 120--140D C.,

i. e., well above the dew point for water and shafts'or chambers 2, Which are constructed'of f light oils. The temperature of all other apparatus provided forin the gas cycle maybe as high as the gasftemperature in the said outlets, so

i that no condensation of steam or oils may occur.

The tar/ or other .constituents from the gas precipitating'in the tar removal arrangement 24 `can be rdrawn off -through the closable pipeline 2'8. The pipeline 28V leads to a settling tank 29, in whichta'ruis separated from viscous matters. The "liquid ltar is removed from the tank 29 through pipeline 30 to a distilling apparatus 3|, for instance a pipe-still arrangement. The distilling4 vapours jand gases, developedv when distilling the tar in the arrangement 3|, are con'- ducted throughpipeline `32 to the dome-like roof ofthe gas heater'l. Here the vapours or'gases are mixed withihighly heated steamand reaction gases, and hydrocarbons are thus transformed into hydrogen, carbon-monoxide and, asY the case may be, some elementary carbon innely divided state. The residuals from the settling tank 29 and from theV distilling apparatus 3I are charged into the fuel feeder V3 and are' thusagain treated in the gas heater,V whereby further carbon compounds are decomposed."

A pipeline 33 leads'from the' gas exhauster 26 to theV lower end of the Ygas heater I0, and interposed in the line is a gas valve 34. The lower end ofthe gas'heater I0 is also connected with the waste gas flue 35, by means of a pipelineSS, governed bythe shut-'01T valve'31,'which ue leads to a chimney not Vshown onthe drawings.

At the lower end of the shaft I Vthere are 'connected'pipelines`38 and 39, each of which includes a 'shut-off'valve V4I). `The pipeline 38 leads to an arrangement 4I andthe pipeline 39 runs to an arrangement`4`2.' The arrangements and 42 are .recuperators YThey serve for Apreheating the air and if 'necessary also fuel gas for'combustion in shaftY 1. In the inside of the recuperators 4I andv 42Y there Aare provided a number of vertical tubes 43,Y which aretraversed by the medium to beV preheated.

"The Ycontriva`nce42 is Yequipped with gas-air burners, '44,'whichv are supplied with fuel-gas and air, .bythe pipeline 45 and 46.

' YThe hot` combustion gases leaving the burner 44 flow'along vthe 'outside of the pipes 43 of the contrivancesf 42, and apart of their heat is transferred through the pipeline 43 and thus to the medium (fuel gas) nowing through these pipesV to 'conduit 39. From the upper end of the recuperator 42 the hot combustion gases flow through the connecting line 41 to the upper end lof theY recuperator 4I, which Similarly 'to the recuperator 42 is fitted inside 'with tubes 43. The hot combustion gases transfer the restA of the useful heat, etc., air flowing through the contrivance 4I toconduit 38, and finally flow through the rpipeline 48 to the channel 35. The recuperat`or 742 is supplied with fuel gas through the pipeline 49 and theV recuperator 4I is supplied with air through the pipeline 50.

The' method of operating the plant as shown, is about the followingI--Iti is assumed, that all partsof the gasproducing plant are heated up to the'wo'rking: temperature, the gas valve 4I) at the foot-of the shaft A1`may beA opened. Preheatedwaifr and fuel gas then flow from 38 to 39 into the shaft lat the lbottom. The gas valve 8 is closed int-his rworking period, likewise the valve 34. The valve 31 ofthe gas heater I 0 is, however,

open.V The media introducedinto the shaft 1 are burnt there( The ho-t gases .'pass through the oonnectingline 9 into the gas heater I0 and they give their heat to'the'refractorychecker-work 5|-, which similarly to a known Cowper stove is surrounded by a refractory brick lining 52.'

As soon as the refractory checkerwork 5| of the gas heater I has been brought to the desired temperature, at which hydrocarbons decompose, for instance up to 1250 C., the gas valves 40 and 31 are closed and the valves 8 and 34 are opened. By means of the blower 26 through the pipeline 33 a mixture of water-gas and steamis now introduced from below into the gas heater I0. The gas-steam mixture is warmed-up at' the hot checkerwork of the gas heater, for instance to a temperature of about 1150-1200 C. 'Ihe mixture then flows through the connection 9 into the shaft 1, passes downwards and then goes through the opened pipeline 6 into the channels and into the longitudinal channels to the ports 4a of the bridges 4. From these ports 4a the hot steam-gas mixture flows into the fuel charge of the gas producer chamber 2. The hot gas-steam mixture gives olf its heat to the fuel, whereby by the conversion of the steam with carbon there is formed water-gas. The temperature inside the fuel charge of the gas producer may be about 1000-1100 C., just above the bridges 4. A part of the formed water-gas is now removed through the cavity |2b and the channels I2C, provided in the annular wall projection above bridges 4 of the gas producer I, to the channel I2. This part of the gas then fiows through the dust separator I3 and pipe I4 to the steam boiler I5. From there the gas passes to the scrubber I1. The purified and cooled gas can finally be discharged through the pipeline 20 as useful 1:2 gas.

The remaining gas formed in the lower part of the lgasification chambers 2 or which has been introduced there into the chambers, rises upwards through the fuel. It warms up the fuel which is thereby distilled. The mixture of water-gas,

distilling gas and steam is drawn off through the pipelines 2| at the ceiling of the gas producer, at a temperature of about 120 C. The openings of the pipelines 2| are situated above the top layer of the fuel, so that the gases and vapours from the gas producer are essentially drawn off at the temperature inherent to the top layer of the fuel charge.

The gases and vapours then flow through the pipelines 2|, the dust separator 22 and the tar precipitator 24. In these contrivances, the dust and tarry constituents contained in the gas only in suspension, are separated, whereas the vapourlike constituents especially hydrocarbon and water-steam are left in the gas. The gas has therefore a temperature which essentially is above the dew point for water-gas.

The gas still hot and charged with steam and hydrocarbons is then delivered by means of the blower 26 through the pipeline 33 into the gas heater. Here it is again heated-up so as to flow afresh into the gas producer I, and to effect here the water-gas reaction. .Under certain circumstances, it is moreover advisable to add a certain quantity of steam to the gas before entering the gas heater l0, as through pipe 33', if the. quantity of water formed during the distillation of theV fuel isV not sufficient for the water-gas reaction. 4Assoon-as the .temperature of the gas heater ID has fallen below the point at which the water-'gas reaction 'graduallyr takes place, rthe valves 8 and'34 areclovsed and the gas heater yafter opening the yvalves 40 and 31 is again heated-up.` -The'rea'fter'the former cycle of the furnaces isfstarte'd,`so thatvWater-gas is again formed; Instead' of connectingv the gas producer with one gasheater only, as shown on the drawings, it is also possible and advantageous to connect thevgasprodfucer alternatively with 2 or several gas heaters. -In'fthis case a continuous stream of water-gas can be permanently taken from the gas producer as always one of `the gas heaters, having a high temperature, is connected with the gas producer.

The hydrocarbons contained in the circulating gas which is introduced into the gas heaters are converted by the interaction with steam in the gas heater or in the lower part of the gas producer, where exists a high temperature, into hydrogen and carbon-monoxides. Consequently, the useful water-gas flowing through the channels of the bridges 4 from the gas producer I contains practically no hydrocarbons and consists exclusively of hydrogen and carbon monoxides.

- The residue left over from the gasification of vthe fuel passes through the spaces between the bridges 4 of the gasification chambers 2 and then flows into the discharging shafts 53.

I have now described my present invention on the lines of a preferred embodiment thereof, but my invention is not limited in all its aspects to the mode of carrying it out as above described and shown, since the invention may be variously embodied within the scope of the following claims.

I claimz-- 1. In a method for producing water-gas containing carbon monoxide and hydrogen in ratio suitable for catalytical reaction, such as the synthesis of hydrocarbons, from bituminousfuel of the character of brown coal, lignite, bituminous coal and the like, comprising: flowing through and thereby reacting with a bed of the fuel, a heated mixture of steam and water-gas which has been previously heated in a separate heating stage of a cycle to a temperature at which hydrocarbons will decompose and interact with steam; withdrawing part of the gas thus produced from the cycle at a point in the fuel bed where the fuel is substantially free of hydrocarbons; returning the other part of said gases in cycle to said heating stage at a temperature above the dew point of tar and water, after passing through another part of the fuel bed where hydrocarbons are present and flow off with the gas in admixture therewith; removing tarry constituents in suspension from the latter gas portion while leaving the vapor-like hydrocarbons therein, after the gas leaves the fuel bed but before it re-enters the heating stage; the step comprising distilling the so removed tar, and conducting the vapors of distillation therefrom back into the aforesaid heating stage into contact with the gas therein.

2. In a method for producing water-gas containing carbon monoxide and hydrogen in ratiol s-uitable for catalytical reaction, such as the synthesis of hydrocarbons, from bituminous fuel of the character of brown coal, lignite, bituminous coal and the like, comprising: flowing through and thereby reacting with a bed of the fuel, a heated mixture of steam and water-gas which has been previously 'heated in a rseparate vheating stage of a cycle to a temperature at which hydrocarbons will decompose and interact with steam; withdrawing part of the gas thus produced fromthe cycle at a point in the fuel bed where the fuel is substantially free of hydrocarbons; returning the other part of `said gases in cycle to said heating stage at a temperature above the dew point of tar and water, after passing through another part of the fuel bed where hydrocarbons are present and flow off with the gas in admixture therewith; removing tarry constituents in suspension from the latter gas portion while leaving the vaporand the nquid tar dimming step, back into the iu fuel bed.

' I-HEINRICH KOPPERS. 

